Dicyclopentadienyl iron, also known as ferrocene, has efficacy when used as a fuel additive to improve combustion quality, reduce pollutant emissions and increase efficiency in fuel combustion systems, including engines, boilers and turbines. For example, U.S. Pat. No. 2,867,516 to Pedersen discloses that ferrocene can be used as a combustion aid in vapor phase as an addition to gaseous hydrocarbon fuel, or as an addition to the air or oxygen employed in supporting combustion. According to the Pedersen patent, heated fuel, air or oxygen can be passed through a bed of ferrocene crystals to vaporize ferrocene and entrain it into the fuel mixture. This type of sublimer is intended to supply the ferrocene and fuel in a predetermined ratio, such as 1:20 to 1:2000 parts by weight of fuel. The patent discloses that when ferrocene is supplied in suitable concentration, the quality of the combustion process is improved, resulting in cleaner combustion products.
Another known use of ferrocene is as a fuel additive, serving as an engine conditioner. U.S. Pat. No. 4,389,220 to Kracklauer discloses a two-stage method of conditioning a diesel engine, resulting in reduced pollutant emissions and increased efficiency in fuel combustion. An initial high dosage of ferrocene, such as 20-30 ppm, in the diesel fuel eliminates carbon deposits from the combustion chambers and deposits a layer of catalytic iron oxide on the combustion surfaces. Thereafter, a lower dosage of ferrocene, such as 10-15 ppm, maintains the catalytic iron oxide coating. It is undesirable to maintain the initial high concentration of ferrocene in diesel fuel, as this will lead to detrimental combustion modifications, minimizing or eliminating the beneficial effects of the catalytic iron oxide wall coating. Therefore, the mere addition of ferrocene to fuel is not entirely satisfactory as a delivery system.
The addition of ferrocene to fuel also is known to enhance gasoline's octane rating. In addition, ferrocene is known to reduce certain exhaust emissions and decrease fuel consumption in gasoline powered vehicles. Schug, K. P., Guttann, H. J., Preuss, A. W., and Schadlich, K., Effects of Ferrocene as a Gasoline Additive on Exhaust Emissions and Fuel Consumption of Catalvst Equipped Vehicles, SAE Technical Paper Series, 1990, paper number 900154.
While ferrocene typically is dissolved in liquid fuel, systems have been devised to deliver other catalytic combustion aids through the air stream into an engine's combustion chamber. For example, U.S. Pat. No. 5,113,804 to Kraus discloses a system for handling a solid phase catalyst consisting of a platinum compound. A metered quantity of the compound is mechanically dispensed onto a heated plate, where it is sublimed and joins the combustion air stream. The metering apparatus is responsive to various parameters, such as fuel consumption rate or emission rate from the combustion process of certain compounds. Addition of a proper concentration of catalyst by this system decreased exhaust emissions of hydrocarbons and produced a lighter color in the engine's exhaust smoke.
As shown, considerable effort has been directed to supplying ferrocene or other catalysts in the combustion mixture in a proper proportion to reduce emissions and condition the engine. With increasing pollution control requirements applicable to combustion equipment, it would be desirable to have a simple and reliable method and apparatus to supply ferrocene in an effective amount. For example, the injection of liquid ferrocene solution into the combustion system of an engine would be desirable. However, the solubility of ferrocene in solvent is limited to about ten percent by weight. With this limited solubility, it would be difficult to carry a large enough reservoir of ferrocene solution on a motor vehicle for long term injection. Similarly, the direct solution of ferrocene in gasoline or diesel fuel is not fully satisfactory, since no single concentration is correct in all cases. In addition, treating each tank of fuel at fill-up is difficult and cumbersome.
Therefore, it would be desirable to have a method and apparatus for supplying ferrocene to an engine other than as an additive to fuel or lubricating oil.
Similarly, it would be desirable to have a method and apparatus for supplying ferrocene in suitable quantity without requiring costly and complex sensors and the like combustion monitoring equipment to meter and regulate the process.
In addition, it would be desirable to have a method and apparatus for supplying ferrocene to a combustion system in a manner that results in improved effectiveness.
To achieve the foregoing and other objects and in accordance with the purpose of the present invention, as embodied and broadly described herein, the method and apparatus of this invention may comprise the following.